Absorbent sheet including bath tissue and paper towel is delivered in roll form. Bath tissue and paper towels are commonly sold as rolls of multi-ply tissue shrink-wrapped in polyethylene. Typically, when the parent roll of tissue is converted to a “log”, the outermost layer in these rolls is lightly adhered to the underlying layer or layers to form a tail-seal. Tail sealing is intended to not only prevent the loose end of the roll from unraveling and interfering with the manufacturing process but also to insure that the package is attractive while facilitating handling of loose rolls by the consumer. However, imperfect tail-sealing often leads to numerous consumer complaints when it interferes with easy removal of the sheet from the roll. In general, complaints referring to improper tail-sealing are among the most common complaints for many absorbent sheet products. In the case of multi-ply products, complaints about ply separation are especially common.
Hot melt adhesives are conventionally used for tail-sealing absorbent sheet as is seen in U.S. Pat. No. 7,799,402 to Redmann et al. and U.S. Pat. No. 4,026,752 to Hartbauer et al. So also, low solids aqueous compositions are sometimes conventionally employed. See U.S. Pat. No. 7,967,933 to Redmann et al. See, also, U.S. Pat. No. 6,342,297 to LaBrash where polyethylene glycol (PEG)/cellulosic tail-seal adhesives are described.
Adhesives for use with absorbent sheet generally are seen in United States Patent Application Publication No. US2015/0090156 of Combs et al., entitled Adhesives That Include Plasticized Starch Derivatives and Methods and Articles Relating Thereto (Celanese Acetate LLC). This reference discloses hot melt adhesive compositions based on starch, cellulose acetate and/or acetins and proposes the use of cellulose nanofibrils as an optional filler and xanthan gum an optional polymeric ingredient. See, also, U.S. Pat. No. 5,858,554 to Neal et al., entitled Paper Product Comprising Adhesively Joined Plies which describes absorbent sheet provided with polyvinyl alcohol or starch adhesive compositions; note Col. 4, lines 20-55.
Nanofibrillated cellulose (NFC) or sometimes referred to as microfibrillated cellulose (MFC) is known in the art to be useful for a variety of purposes, including for use as a structural material in sheet and related articles. For example, in U.S. Pat. No. 6,734,335 it is mentioned that NFC is useful in absorbent structures. Col. 22, lines 13+. See, also, U.S. Pat. No. 7,614,110, Col. 13, lines 38+. United States Patent Application Publication No. US 2012/0219816 discloses use of NFC as a layer in a multilayer paperboard structure, Abstract. See, generally, United States Patent Application Publication No. US 2012/0058536, ¶[0151], which discloses NFC as a structural material. NFC is used in molded structures, as seen in United States Patent Application Publication No. US 2009/0308552, ¶[0001], as well as United States Patent Application Publication No. US 2011/0263756, Abstract. NFC is, likewise, known for use in adhesives. JP 60250079 discloses a liquid adhesive made by blending a polyvinyl acetate emulsion, sodium carboxymethylcellulose and above 3-4% NFC based on the weight of the liquid composition. See, also, United States Patent Application Publication No. US 2010/0285295, ¶[0023], where NFC is mentioned as a filler for an adhesive resin; United States Patent Application Publication No. US 2011/0052881, ¶[0062], having similar discussion, as well as United States Patent Application Publication No. US 2009/0042003, ¶[0057].
Despite the availability of numerous adhesive materials and methods of tail-sealing, effective tail-sealing of rolled goods remains a significant problem in terms of manufacturing and customer satisfaction.